Salam yeah i heard a talk with hamza Yusuf and he was saying if you in your dua call upon allah with his hidden names ie "O Allah I seek your help with my problems and I call upon your names which you have revelaed and the ones hidden" the Allah (SWT) does not refuse the dua.

Also has anyone heard the hadith in which the prophet is reported to have said "Allah has 99 names 100 less one and who ever learns these of by heart will enter jannah" what is the real meaning of it because we know Allah has more than 99 names in the quran and sunnah as kadafi said?